STM32F051x
Electrical characteristics
Table 61. TIMx(1) characteristics (continued)
Symbol
Parameter
Conditions
Min
Max
Unit
1
tCOUNTER 16-bit counter clock period
fTIMxCLK = 48 MHz 0.0208
65536
1365
tTIMxCLK
µs
tMAX_COUNT
Maximum possible count
with 32-bit counter
fTIMxCLK = 48 MHz
-
-
65536 × 65536
89.48
tTIMxCLK
s
1. TIMx is used as a general term to refer to the TIM1, TIM2, TIM3, TIM6, TIM14, TIM15, TIM16 and TIM17
timers.
Table 62. IWDG min/max timeout period at 40 kHz (LSI) (1)
Prescaler divider PR[2:0] bits
Min timeout RL[11:0]=
0x000
Max timeout RL[11:0]=
0xFFF
Unit
/4
0
0.1
/8
1
0.2
/16
2
0.4
/32
3
0.8
/64
4
1.6
/128
5
3.2
/256
6 or 7
6.4
409.6
819.2
1638.4
3276.8
ms
6553.6
13107.2
26214.4
1. These timings are given for a 40 kHz clock but the microcontroller’s internal RC frequency can vary from
30 to 60 kHz. Moreover, given an exact RC oscillator frequency, the exact timings still depend on the
phasing of the APB interface clock versus the LSI clock so that there is always a full RC period of
uncertainty.
Table 63. WWDG min-max timeout value @48 MHz (PCLK)
Prescaler
WDGTB
Min timeout value
Max timeout value
Unit
1
0
0.0853
5.4613
2
1
4
2
0.1706
0.3413
10.9226
ms
21.8453
8
3
0.6826
43.6906
Doc ID 022265 Rev 3
85/105